Stock-Based Compensation - Fair Value Assumptions (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) item $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares
Additional information
Stock-based compensation expense	$ 10.6	$ 6.9	$ 5.9
Stock Options
Other information
Total fair value of options vested	$ 0.4
Nonvested Options, Shares
Nonvested at end of year (in shares) | shares	0
Additional information
Vesting period	3 years
Restricted Stock and Restricted Stock Units
Other information
Compensation expense yet to be recognized	$ 1.5
Weighted-average period over which compensation cost will be recognized	1 year 9 months 18 days
Shares
Unvested at beginning of year (in shares) | shares	120,000
Granted (in shares) | shares	67,000
Vested (in shares) | shares	(72,000)
Unvested at end of year (in shares) | shares	115,000	120,000
Weighted Average Grant Date Fair Value
Unvested at beginning of year (in dollars per share) | $ / shares	$ 45.21
Granted (in dollars per share) | $ / shares	76.73	$ 39.03	$ 51.02
Vested (in dollars per share) | $ / shares	54.53
Unvested at end of year (in dollars per share) | $ / shares	$ 57.74	45.21
Additional information
Fair value of shares vested	$ 3.9
Weighted-average fair value (in dollars per share) | $ / shares	$ 76.73	$ 39.03	$ 51.02
Aggregate intrinsic value of restricted stock vested	$ 5.5	$ 2.9	$ 3.5
Performance Stock Units
Other information
Compensation expense yet to be recognized	$ 1.1
Weighted-average period over which compensation cost will be recognized	1 year 4 months 24 days
Additional information
Vesting period	3 years
Types of performance units | item	2
Percentage of units measured on stock price relative to peer group	50.00%
Percentage of units measured on stock price based on pre determined EPS	50.00%
Period for which shareholder return is compared with peer group for units determined by EPS performance	3 years
Calculated fair market value	$ 10.2
Value of PSUs granted	3.6
Stock-based compensation expense	$ 5.7	$ 2.7	$ 1.9
Performance Stock Units | Minimum
Additional information
Performance measures for dollar denominated award granted	0
Performance Stock Units | Maximum
Additional information
Performance measures for dollar denominated award granted	2.0